When the weather doesn't change: rainy streaks, dry streaks, cloudy streaks and sunny streaks

You've probably heard people say something like this:  "We have a saying around here.  If you don't like the weather, wait a minute."  Almost everywhere I've visited, I've heard some variant of this expression.  It always struck me as funny, because it implies some kind of unique changeability in the local weather, and yet people everywhere seem to say this!

I've certainly heard people say this about Victoria, but if anything, I think that what's more unique about Victoria's weather, at least compared with other places in Canada, is not its changeability - lots of places have changeable weather - but its stability.  For one thing, the temperatures tend not to fluctuate as much as they do in other parts of Canada.  In addition, we often get long stretches of similar weather, which can be both good and bad.  In the summer, we get long stretches of sunny, dry weather, but in the late fall and winter we often get long stretches of cloudy and rainy weather.  I thought I would take a look at the longest such stretches ever recorded in Victoria.

Let's start with precipitation.  The greatest number of consecutive days with measurable rainfall at the Victoria Gonzales weather station was 29 days: November 2-30, 2006.  Keep in mind that this doesn't mean it rained non-stop for 29 days; it just means that there was at least 0.2 mm of rain measured during each of those days.  That means it could be sunny all day, then a brief sprinkle of rain in the evening, and it would still be considered a day with measurable precipitation.  In fact, there was nearly 40 hours of sunshine recorded during this 29-day rainy streak, an average of nearly 1.4 hours per day.   Nonetheless, 29 days in a row with measurable rainfall is a long stretch!  The second longest stretch was 23 days and the third longest was 20 days.

On the flip side, the longest stretch without precipitation was 63 days, from June 15 to August 16, 1926.  The second longest stretch was 54 days, from July 17 to September 8, 1986.  During that stretch, there were 605 hours of sunshine recorded, or an average of 11.4 hours per day.  The third longest dry streak was 51 days, from July 7 to August 26, 1951.  Although shorter, that stretch came with even more sunshine: 653 hours, or an average of 12.8 hours per day.  There was a tie for the fourth longest dry streak: 46 days in both 1985 and 1991.  The latter streak is unusual in that it didn't occur during July or August; it was from September 1 to October 16, 1991.  Lengthy dry streaks are quite common in Victoria during the summer drought period.  Over the past 105 years, the average summer dry streak in Victoria has been 29 days.

Consecutive sunless days are actually much less common in Victoria than consecutive days with rainfall.  The longest stretch of days with no measurable sunshine was 9 days, from January 6-14, 1967.  You only need to have 0.1 hours of sunshine - 6 minutes - in a day in order for it to be considered a day with measurable sunshine, so you can see why really long stretches might be uncommon.  However, even if you look at consecutive days with less than 1 hour of sunshine, the longest stretch is still only 10 days, from December 8-17, 1980.  The longest stretch of days with less than 2 hours of sunshine is 12 days, recorded in both 1953 and 1971.  So you can see that long stretches with little or no sunshine are actually quite rare in Victoria.

Finally, if you look at the longest stretch of days with measurable sunshine, it was 124 days from May 27 to September 27, 1986.  Perhaps not surprisingly, this period included the record breaking 54 day dry streak discussed above.  Measurable sunshine is a pretty low bar, since you only need at least 0.1 hours of sunshine each day.  If you look at number of consecutive days with at least 8 hours of sunshine, the record is 32 days, from July 17 to August 17, 1977.  During this very sunny period, there were 434 hours of sunshine, and in fact all but one day during this period had more than 10 hours of sunshine and all but 5 days had more than 13 hours of sunshine.   Another remarkable sunny stretch occurred in 1985, when there was 635 hours of sunshine from June 15 to July 29, an average of 14.1 hours per day.  There was just one day during this 45-day stretch with less than 10 hours of sunshine, and a total of just 3 days with less than 12 hours of sunshine.  Perhaps not surprisingly, this stretch included most of July 1985, which was the sunniest calendar month on record at Victoria Gonzales, with 426 hours of sunshine.